The minority administration of 39 councillors was formed with the support of the Greens and independents and brings an end to the exclusive Tory control of the council under the cabinet system which excludes the majority of councillors and concentrates power on the largest minority.
Tory supporting blogs like Guido Fawkes and ConHome have unsurprisingly criticised the loss of a council claiming it as evidence that a vote for UKIP means a vote for Labour, referring to the fact that the council now has a Labour leader. The council isn't Labour controlled though, it is jointly controlled by UKIP, Labour and the Lib Dems and because it's a minority administration (39 UKIP, Labour and Lib Dem councillors versus 40 Conservatives) it will need the support of some or all of the Tories, Greens and independents to implement policy meaning most people in Norfolk are represented in the decision making process, not the biggest minority in political terms.
UKIP isn't an offshoot of the Conservative Party and it's ridiculous to assume that a group of UKIP councillors would automatically support the Tories as the lesser of two evils. There is no whip in UKIP so councillors are free (and expected) to determine what is right for their local area. If that doesn't involve the Tories then tough, they should have done a better job when they had the opportunity.
The cabinet system of local government, like the First Past the Post system that supports it, is an undemocratic anachronism and hopefully more councils will change back to multi-party committees.